Blimp-1 connects the intrinsic and extrinsic regulation of T cell homeostasis
JOURNAL OF CLINICAL IMMUNOLOGY
Authors: Nutt, Stephen L.; Kallies, Axel; Belz, Gabrielle T.
Abstract
The body tends to maintain a relatively constant number of peripheral T cells, a phenomenon termed T cell homeostasis. Homeostasis is controlled by the coordinated activity of extrinsic regulation, most notably through cytokines of the common gamma chain (c gamma C) family and intrinsic regulation by transcription factors. Whereas the former mechanism has been extensively studied and is relatively well characterized, the transcription factors that govern the homeostasis of late-stage effector and memory T cells have been less well defined but include regulators such as T-bet, Eomes, Bcl6, and Id2. The transcriptional repressor, Blimp-1 is well known as a master regulator of the terminal differentiation of B cells into antibody secreting plasma cells. Recent experiments have now revealed that Blimp-1 is also a key regulator of T cell differentiation. Blimp-1 is expressed in differentiated effector T cells and controls their homeostasis. Interestingly, Blimp-1 expression is controlled by the same c gamma C cytokines that regulate T cell homeostasis suggesting a direct link between the extrinsic and intrinsic arms of the process.
Sequences analyses and expression profiles in tissues and embryos of Japanese flounder (Paralichthys olivaceus) PRDM1
FISH PHYSIOLOGY AND BIOCHEMISTRY
Authors: Liu, Conghui; Liu, Wei; Fan, Lin; Liu, Jinxiang; Li, Peizhen; Zhang, Wei; Gao, Jinning; Li, Zan; Zhang, Quanqi; Wang, Xubo
Abstract
PRDM1 (PRDI-BF1-RIZ1 homologous domain containing 1) appears to be a pleiotropic regulatory factor in various processes. It contains a PR (PRDI-BF1-RIZ1 homologous) domain protein and five zinc fingers. In the present study, a gene coding the homolog of prdm1 and the 5' regulatory region of prdm1 was identified from the Paralichthys olivaceus (denoted Po-prdm1). Results of real-time quantitative polymerase chain reaction amplification (RT-qPCR) and in situ hybridization (ISH) in embryos revealed that Po-prdm1 was highly expressed between the early gastrula and tail bud stages, with its expression peaking in the mid-gastrula stage, whereas the results of RT-qPCR and ISH in tissues demonstrated that Po-prdm1 transcripts were ubiquitously detected in all tissues, which indicates its pleiotropic function in multiple processes. ISH of gonadal tissues revealed that the transcripts were located in the nucleus and cytoplasm of the oocytes in the ovaries but only in the spermatogonia and not in the spermatocytes in the testes. The Po-prdm1 transcription factor binding sites and their conserved binding region among vertebrates were analyzed in this study. The combined results suggest that Po-PRDM1 has a conserved function in teleosts and mammals.